public class USB_interface {
    public static void main(String args[]){
        Mouse usb1 = new Mouse();
        usb1.work();
        usb1.stop();
        USB usbs[] = new USB[2];
        usbs[0] = new UPan();
        usbs[1] = new Mouse();
        for (USB usb : usbs) {
            usb.work();
            usb.stop();
        }
    }
}

interface USB{
    void work();
    void stop();
}

class Mouse implements USB{
    public void work(){
        System.out.println("我点点点");
    }
    public void stop(){
        System.out.println("我不能点了");
    }
}

class UPan implements USB{
    public void work(){
        System.out.println("我存存存");
    }

    public void stop(){
        System.out.println("我走了");
    }
}